Get TLS certificate from smtp server

Posted on by

Mini guide how to extract the public certificate from at SMTP server using TLS

openssl s_client -connect mail.example.com:25 -starttls smtp
Download OpenSSL for windows here: https://slproweb.com/products/Win32OpenSSL.html

copy Server certificate section from
-----BEGIN CERTIFICATE----- to
-----END CERTIFICATE-----
and save to a .cer file, and open the file

source: https://serverfault.com/questions/131627/how-to-inspect-remote-smtp-servers-tls-certificate

Leave a Reply